# CVE-2026-74695: netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref()

> A missing reference count drop in Linux kernel netfilter flowtable offload causes memory leaks and kernel warnings, potentially leading to denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-97100, BELL-CVE-2026-74695, DEBIAN-CVE-2026-74695, GHSA-cx4h-xjm7-pqxp, UBUNTU-CVE-2026-74695

## What is CVE-2026-74695?

CVE-2026-74695 is a high-severity memory corruption vulnerability in Linux, published on 22 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref()

Incoming skbs passing through netfilter flowtable offload hooks (or XFRM
offload path) might already carry a ref-counted dst_entry assigned during
earlier RX or routing steps.

Calling skb_dst_set_noref() when skb already holds a ref-counted dst
overwrites skb->_skb_refdst, leaking the previous dst_entry reference
count and triggering a DEBUG_NET_WARN_ON_ONCE assertion in
skb_dst_check_unset():

  WARNING: at skb_dst_check_unset include/linux/skbuff.h:1170
  WARNING: at skb_dst_set_noref include/linux/skbuff.h:1234
  WARNING: at nf_flow_offload_ip_hook+0xf6c/0x2b60 net/netfilter/nf_flow_table_ip.c:864

Drop any existing dst_entry reference with skb_dst_drop(skb) before
setting the non-referenced flowtable destination.

## Which versions are affected by CVE-2026-74695?


## How do I fix CVE-2026-74695?

Apply the vendor's patch.

## Is CVE-2026-74695 being exploited?

There is no known exploitation of CVE-2026-74695 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74695 and fix it if it is affected.

What it is: CVE-2026-74695 is a high-severity memory corruption vulnerability in Linux, published on 22 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74695 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74695/ (Markdown: https://insights.sbomify.com/CVE-2026-74695/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74695
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74695
- OSV: https://osv.dev/vulnerability/CVE-2026-74695

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74695/
Summaries are generated and may contain mistakes; the official description above is the record.